This is a Phase 1, single-site, open-label, single dose study of the absorption, metabolism and excretion of radiolabeled AT1001 in healthy male subjects between 30 and 55 years of age, inclusive. Six subjects will be dosed, with the goal of having at least 4 subjects complete the study through follow-up. All subjects will be screened within 28 days before admission to the Clinical Unit. Subjects will be confined to the clinical unit for 10 days after dosing and will return to the clinic for a follow-up visit 28 days after dosing.